JUST SHORT:
Steve Weatherford of the Jets is knocked out of bounds by Anthony Smith on a fake punt.Getty Images

Rex Ryan said the Jets had given Steve Weatherford instructions regarding a fake punt — it’s got to be a reasonable distance to get the first down.

The problem is, the Jets punter wasn’t sure how many yards he needed.

“We told him before that it needed to be a manageable situation,” Ryan said yesterday, “not fourth-and-20 or whatever it was.”

In truth, it was fourth-and-18 from the Jets’ 20-yard-line with 6:36 to go in the first quarter of yesterday’s 9-0 loss to the Packers. Weatherford, surprisingly, made the on-field call himself to try to run for a first down, in part because he was unsure what the distance was.

“It would have been a good decision had it been fourth-and-9, but that’s my fault,” Weatherford said.

Ryan said, “I don’t think he realized we’d just been sacked” — on third-and-9, Mark Sanchez took a 9-yard loss.

“Yeah, at the time, I knew it was third-and-9 when I went out there. I didn’t see exactly how many yards we lost on the sack,” he said. “Once I get out of the pocket, I feel like if it’s 12 or 15 yards, I think I can make it.”

But the punter came up 1 yard short on fourth-and-18, and Ryan said Weatherford should have kicked.

“He does it on his own. He’s a great athlete,” Ryan said. “He did it last year against Miami, but in that situation, it probably would have been wiser to punt.”

Weatherford initially was credited with an 18-yard run before he was knocked out of bounds, so the Jets thought they had the first down. But the Packers successfully challenged the call — Weatherford was knocked out a yard shy.

It was early, but in a scoreless game, the failed conversion gave the Packers tremendous field position at the Jets 36. Four plays later, Mason Crosby booted a 20-yard field goal to put Green Bay on top.

“I was 50-50 on whether I made it because I know the guy hit my foot. I just didn’t know if my foot had gone out of bounds,” Weatherford said. “I knew I got the ball over the first down [marker], but I wasn’t sure about what happened with my feet.”

Weatherford said he wasn’t told not to fake in that situation.

“I watch film all week for formations that I feel would be good for that particular play,” he said. “… It could have been a huge swing for us in the game, but obviously we came up about a half-yard short.”